1. Department of Biological Science, Graduate School of Science; Hiroshima University; Kagamiyama 1-3-1, Higashi-Hiroshima 739-8526 Japan
2. Natural History Museum and Institute; Chiba, Aoba-cho 955-2, Chuo-ku, Chiba-shi, Chiba 260-8682 Japan
3. Miyajima Natural Botanical Garden, Graduate School of Science; Hiroshima University; Mitsumaruko-yama 1156-2, Miyajima-cho, Hatsukaichi 739-0543 Japan
4. Biology Department; University Brunei Darussalam; Jalan Tungku Link, Gadong BE1410 Brunei Darussalam